1. Field of the Invention
The present invention relates to a capsule endoscope performing various medical treatments including examinations and treatments in a body cavity in a subject, and to an intrasubject medical system using the same; in particular, the present invention relates to a capsule endoscope having a string whose one end is attached to a main body of the capsule endoscope and whose another end is arranged outside a subject, and to an intrasubject medical system using the same.
2. Description of the Related Art
In recent years, swallowable capsule endoscopes appear in the field of endoscope. The capsule endoscope has an imaging function and a radio communication function. The capsule endoscope has a function of traveling through inside a body cavity, such as an interior of an internal organ such as stomach and small intestine, following peristaltic movements thereof and sequentially capturing images after being swallowed by a patient from the mouth for an observation (examination) until naturally excreted from a human body.
While traveling inside the body cavity, image data captured inside the body by the capsule endoscope is sequentially transmitted to an outside by radio communication, and is stored in a memory provided in an external receiver. When the patient carries the receiver which has a radio communication function and a memory function, the patient can move freely even during a period after swallowing the capsule endoscope until excreting the same. Thereafter, a doctor or a nurse can make diagnosis by displaying an image of an organ on a monitor based on the image data accumulated in the memory.
Here, since the capsule endoscope described above is small and easily swallowable, images inside the subject can be easily obtained without the need of anesthesia in comparison with an ordinary endoscope. It is possible to attach one end of a string to a main body of the capsule endoscope and arrange another end outside the body, and manipulate the string from outside the body to control a position of the capsule endoscope so as to obtain a desirable image (see, for example, Japanese Patent Application Laid-Open No. 2004-181250 and Japanese Patent Application Laid-Open No. 2000-33070).
On the other hand, there is a capsule endoscope in which a magnet is embedded in a main body thereof; a rotating magnetic field is applied externally to rotate the magnet, and in turn, to rotate the capsule endoscope, whereby the capsule endoscope is made to freely move inside the subject (see, for example, Japanese Patent Application Laid-Open No. 2004-229922).
However, when the conventional capsule endoscope to which a string is attached as described above is used, a problem arises; namely, the attached string successively rubs against a pharyngeal region thereby hurting the pharyngeal region.
Further, when the conventional capsule endoscope which is rotated by the external rotating magnetic field is made to move inside an organ such as stomach that has a wide space, the capsule endoscope sometimes becomes unable to move off from a specific wall, and this raises a problem that a desirable image cannot be obtained.